When you're 67 and basically retired (as Einstein was at this time)?
By contrast, in his 20s, he wrote 4 highly-influential papers in a single year, in his spare time while also working full-time at the Swiss patent office.
By contrast, in his 20s, he wrote 4 highly-influential papers in a single year, in his spare time while also working full-time at the Swiss patent office.
Nah, this wasn't work, that sounds more like the hobby that's in love-hate relationship with the work (need work to live, but it takes time and energy from the hobby).
What’s important is not how much one suffers but how much benefit one adds to the society